Disclosure that laboratory tests have detected traces of contamination in several major brands of infant formula generated concern and confusion Wednesday, with a national consumer’s group and the Illinois attorney general demanding a Food and Drug Administration recall and the federal agency saying it had released inaccurate information on what chemicals were found in which top selling products.

As worried parents called manufacturers looking for guidance about the presence of melamine and a key byproduct in U.S.-made formula, the FDA reiterated its position that the baby food is safe and parents should continue feeding it to their babies, contending the extremely low levels of contamination do not present a health danger. Also, a spokesman for a major manufacturer criticized the FDA for its release of the inaccurate information.

“We’re getting inundated by calls from moms confused about the situation,” said Pete Paradossi, a spokesman for Mead Johnson, one of the three major manufacturers of U.S.-made formula involved in the problem detections.

Melamine is the industrial chemical found in Chinese infant formula — in far larger concentrations — that has been blamed for killing at least three babies and making at least 50,000 others ill. The FDA and other experts said the melamine contamination in U.S.-made formula had occurred during the manufacturing process, rather than intentionally as was done in Chinese production. The manufacturers insist their products are safe.

“The levels that we are detecting are extremely low,” said Dr. Stephen Sundlof, director of the FDA’s Center for Food Safety and Applied Nutrition. “They should not be changing the diet. If they’ve been feeding a particular product, they should continue to feed that product. That’s in the best interest of the baby.”

Part of the confusion Wednesday stemmed from the FDA’s own statements.

While proclaiming that the very low concentrations detected of melamine and a similar compound called cyanuric acid pose no health danger to infants, the FDA has maintained it is unable to identify any exposure level of melamine in infant formula “that does not raise public health concerns.”

Further complicating the situation was inaccurate data that FDA released to The Associated Press, which was first to disclose the formulas’ brand names and other details in an investigative report Tuesday. A spreadsheet the AP obtained from the FDA under a Freedom of Information Act request stated that Mead Johnson’s Infant Formula Powder, Enfamil LIPIL with Iron, contained traces of melamine.